A Human Machine Interface (HMI) is a medium for interacting and exchanging information between a system and a user, which is responsible for receiving operation instructions of a user and responding to the operation instructions. In the actual operation processes, the response of the human-machine interface with respect to the operation instructions of the user often has some delay. The specific delay time depends on the operation load of the human-machine interface, that is, the delay of the response with respect to the operation instructions will be longer when the operation load of the human-machine interface is heavier. However, a longer delay easily makes the user to mistake that the human-machine interface does not respond to the operation instruction, and thus continue to issue the operation instruction which has not responded by the human-machine interface repeatedly, which further increases the operation load of the human-machine interface, and even cause the crash of the operation of the human-machine interface.
In order to solve the above-mentioned problems, there are two main methods provided by the prior art: one is to suspend the response with respect to the operation instruction of the user when the human-machine interface is busy, that is, the operation load is heavier, until the human-machine interface is idle; the other is to receive and forward the operation instruction of the user to the human-machine interface via an operation instruction queue, and then the human-machine interface can respond to the operation instruction.
However, the above-mentioned first method of the prior art completely suspends responding to the operation instruction of the user, which is liable to cause the loss of effective operation instructions issued by the user while the human-machine interface is busy. The second method does not consider that the human-machine interface is busy or idle, and stores all the received operation instructions to the operation instruction queue. Since all the operation instructions in the operation instruction queue will eventually be called and executed by the human-machine interface, the backlog of a plenty of invalid operation instructions will be caused if the user repeatedly issues the operation instruction for multiple times while the human-machine interface is busy, which increases the follow-up operation burden of the human-machine interface, and thus greatly affecting the user's experience.